Rodenticide composition



Patented May 29, 1951 UNITED STATES OF FIQCE 2,554,756 7 RODENTICIDE COMPOSITION Franklin D. Smith,-- St. Louis, M6,, assignor to Monsanto Chemical Company; 'St. Iioui's,-- Mo., a corporation of Delaware No Drawing. Application J uly 29; 1946, Serial No. 686,952

the market, but" most all possess'the undesirable and dangerous characteristic, that if noten tirely' consumed by the intended victim, carelessly spilled or'other-wise unknowingly left unguarded, the poison remains a serious threat" for'ex't'ended periods to all animals or persons who might inadvertently consume or contact the toxic residue.

The object of this invention is toprovide new compositions useful as rodenticides and in' sectivoricides, a small amountof'wh'ich'is' defi-' wherein R is a radical containing 1 to 4 carbon atoms selected from the group consisting ofalliyl, haloalkyl, alkenyl, or cycloalliyl; are highly desirable as the toxic agents inrodenticide-and: insectivoricide compositions. I prefer to use thehexaethy-l ester of tetrapolyphosphoric acid inmy rodenticide and insectivoricide compositions. For example, it hasbeen found that the hexaethyl ester of tetrapolyphosplioric acid when consumed by rats in amounts as small as .005 ml. (0.0065 gram) per kilogram body weight is definitely fatal; similarly, death results when as little as 0.2 ml. (0.26 gram) ofhexaethyltetrapolyphosphate per kilogram of body weight is applied externally to rats.

It takes several days of prolonged contact with moisture for the hydrolysis of the'toxicant in the composition of the present invention to be complete. This-allows sufficient time to poison the rodent or insectivore, but insures that any unconsumed poison will not be available at a later time to inadvertently poison other'ani'mals: This hydrolysis reaction may be retarded by combin hexa ester or an oil solution thereof;

2 ing the toxicmaterial with oils, a process to be fully described in later paragraphs.

While I preferably use the hexaethyl ester of te'trapolyphosphoric acid in my compositions, the

hexamethyl, hexapropyl, hexabutyl and their halogen substitution products exhibit marked toxicity toward rodents and insectivores. In a similar manner the hexaalkenyl esters of tetrapolyphosphoric acid, such as the hexaacrylyl ester are effective as rodenticides. Likewise, hexacyclopr'opyl and hexacyclobutyl esters may be used as the lethal agent in the compositions;

While I have found that baits containing of 1% to 20% of hexa esters'of tetrapolyphosphoric acid are efie'ctive as rodenticides and insectivori cides, and concentrations of to 1% to 10% are equally useful, I prefer concentrations of /2: of 1% to 5% asthe'range effective for most all rodents and insectivores encountered.

The hexa esters of tetrapolyphosphoric acid may be prepared in the manner illustrated by the preparation of hexaethyltetrapolyphosphate: 1' mole of: triethylorthophosphate is heated to 150 0., with stirring and refluxing, and slowly in adropwise manner /3 mole of phosphorous oxychloride is added. The esterification is completed-by refluxing at a temperature below 150 0., for 30 minutes after all the phosphorous oxychloride has been added. The reaction product' is the hexaethyl ester of tetrapolyphosphoric acid and may beused as the toxic ingredient of my composition without further treatment. These hexa esters of tetrapolyphosphoric acid may also be prepared in the manner illustrated by the preparation of the hexamethyl ester of tetrapoly-phosphoric acid: grams of P205 were slowly and with stirring added to 280 grams of trimetliylcrthophosphate in a water cooled reaction vessel, and the stirring continued until all the P205 had reacted.

The compositions ofmy invention may be prepared for efiective presentation to the rodent in various ways. For example, the hexa ester may be mixed with a carrier as edible oils, such as cottonseed oil, soybean oil, corn oil, fish oil, tallow, lard or drippings, or light oils such as mineral oil, and used as such or combined with a food or cereal product such as bread, flour, oatmeal, bran, barley flour or cornmeal, or

other meals such as alfalfa or clover meal. The

composition with cereals may be used in the meal" form or the meal may be pelleted or briquetted for ease in handling, placing, and distribution. As an alternative, the meal may be pelleted and thereafterimpregnat'ed' with the My preferred method is to prepare an oil concentrate wherein the hexa ester of tetrapolyphosphoric acid selected for the rodenticide or insectivoricide is mixed with one of the above described oils. A bait is then prepared comprising the concentrate which is mixed withor poured over one of the cereal or food products and allowed to soak or steep until all of the oil concentrate is absorbed. A toxic bait which will be efiective for several days may be prepared by mixing water and one of the toxicheXa esters of tetrapolyphosphoric acid and soaking or steeping bread, cereal meal or cereal: pellets in the aqueous solution. Also, a toxic oil composition may be prepared and used as an oil rodenticide by mixing 0.5% to 20% of 'a "hexa ester of tetrapolyphosphoric acid with oneof the above described oils. Other toxicants may be incorporated in the composition if desired, although the compositions are outstandingly effective without such additional toxicants.

The hexa esters possess such a high toxicity that it is undesirable to attempt to use them as rodenticides or insectivoricides in high concentrations or without the aid of a carrier or diluent. Also at the higher concentrations, the slight odor of the hexa esters becomes more difficult to mask, and the rodents will be repelled rather than attracted to the bait.

The following examples are for the purpose of illustrating the utility and methods of preparing toxic baits for presentation to rodents and insectivores, but it is not intended that the scope of the invention be limited by the examples.

Example I An effective rodenticide and insectivoricide composition may be prepared by mixing together 98.7 grams of corn oil and 1.3 grams (1 ml.) of the hexaethyl ester of tetrapolyphosphoric acid with sufiicient aniseed oil to give the composition a faint odor attractive to rodents. While this composition is a concentrate and is intended to be mixed with other diluents and carriers, it may be used as a rodenticide as such by placing it conveniently for rodent consumption or contact. Concentrates prepared in this manner may contain up to 40 ml. of the hexa ester of tetrapolyphosphoric acid to 100 grams of oil and still be desirable as a rodenticide and insectiv'oricide.

Example II The 100 grams of concentrate prepared in Example I is poured over 100 grams of pelleted cereal meal and'mixed until all of the oil is taken up by the pellets. The poisoned bait is then placed where it may be conveniently eaten by the rodent or insectivore.

Example III 20.0 ml. of hexachlorethyltetrapolyphosphate is mixed with 98.7 ml. of Water to which is added sufiicient aniseed oil to mask the faint odor of the phosphate ester. This aqueous mixture is added to 100 grams of cornmeal and mixed well. The aqueous compositions are desirably used as soon as possible after preparation.

Example IV ml. of hexaethenyltetrapolyphosphate is mixed with 98.7 ml. of soybean oil and suflicient aniseed oil to mask the odor of the ester. This oil is then poured over 200 grams. of chopped or ground bacon rind, cracklings, or ground meat and mixed well. This is an effective bait for rats and moles.

Example V 10 ml. of hexabutyltetrapolyphosphate is mixed with 85 grams of cotton seed oil to which is added sufficient aniseed oil to mask the faint odor of the phosphate ester. This toxic mixture is, then poured over 300 grams of alfalfa meal and mixed until all of the oil is absorbed by the meal. The meal may then be pelleted or briquetted to form an efiective bait for rats and moles.

,. Example VI ml. of hexamethyltetrapolyphosphate is mixed ,into 95- rams of lard. Sufficient aniseed oil is added to mask the odor of the ester, and the toxic mixture isthen spread on to 400 grams of bread.

Example VII 5 ml. of hexacyclomethylpropyltetrapolyphosphate is mixed with 95 grams of a light mineral oil and 400 grams of oatmeal and may be used as an effective rodenticide and insectivoricide.

I claim:

1. A rodenticide and insectivoricide composition comprising a processed food product and 0.5 to 20% of the hexa ester of tetrapolyphosphoric "acid, the said ester residue being a radical containing from 1 to 4 carbon atoms selected from the group consisting of alkyl, alkenyl and cycloalkyl.

2. A rodenticide and insectivoricide composi-' tion comprising an edible oil and 0-5 to 20% of a hexa ester of tetrapolyphosphoric acid having as ester residues radicals containing from 1 to 4 carbon atoms selected from the group consisting of alkyl, alkenyl and cycloalkyl.

3. A rodenticide and insectivoricide composition comprising an edible oil and 0.5% to 20% of hexaethyltetrapolyphosphate.

4. A rodenticide and insectivoricide composition comprising an edible oil, a cereal product.

and 0.5% to 20% of hexaethyltetrapolyph0sphate.

5. A rodenticide and insectivoricide composition comprising a processed food product and 0.5% to 20% of hexaethyltetrapolyphosphate. FRANKLIN D. SMITH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,146,356 Schrader Feb. 7, 1939 2,402,703 Woodstock June 25, 1946 FOREIGN PATENTS Number Country Date 333,216 Great Britain Aug. 6, 1930 311,935 Italy Oct. 16, 1933 OTHER REFERENCES page 2231. 

1. A RODENTICIDE AND INSECTIVORICIDE COMPOSITION COMPRISING A PROCESSED FOOD PRODUCT AND 0.5 TO 20% OF THE HEXA ESTER OF TETRAPOLYPHOSPHORIC ACID, THE SAID ESTER RESIDUE BEING A RADICAL CONTAINING FROM 1 TO 4 CARBON ATOMS SELECTED FROM THE GROUP CONSISTING OF ALKYL, ALKENYL AND CYCLOALKYL. 